This invention relates to chain links, and, more particularly, to chain links which can be used in a low backline pressure chain.
When transporting articles by means of a conveyor, there are many instances in which the articles will back up or accumulate on the conveyor. When articles accumulate, they push against each other, building up backline pressure. A large backline pressure is unacceptable when the articles being carried by the conveyor are fragile, because the force of the articles pushing against each other tends to damage them. The backline pressure also puts an extra load on the conveyor and sprockets and causes sliding friction and abrasion of the conveyor.
This problem has been dealt with in the past by mounting rollers in a conveyor frame and driving the rollers by means of a number of small belts such that the rollers slip relative to the shafts when backline pressure begins to build up. This is a relatively complicated system and involves considerable maintenance work in order to keep all the belts operating. Furthermore, this arrangement is not self-cleaning, and therefore the rollers would tend to jam if broken glass or other bits of material fall between the rollers.
Another method of handling backline pressure is by attaching sets of carriers to roller chains, such that each carrier has slots in its upper surface adapted to receive a shaft, and each shaft has a roller mounted on it.